Facing the Palazzo dei Diamanti across the top of the Addizione Erculea, the Palazzo Prosperi-Sacrati has the finest doorway in Ferrara — a magnificent marble portal whose carved decoration includes sea monsters, foliage, and portrait busts, attributed to the workshop of Biagio Rossetti. The door, completed around 1493, is so elaborately carved that it takes several minutes of slow looking to work out all its elements.
The palace itself is partly open to the public when hosting temporary exhibitions. The facade is more restrained than the doorway suggests: plain brick above the marble base, in the understated Renaissance manner. Stand at the top of Corso Ercole I d'Este and look south to see both palaces framing the view down to the Este Castle — one of the best urban vistas in Emilia-Romagna.